Over the past five years it has become apparent that endogenous pyrogen, leukocyte endogenous mediator, and lymphocyte activating factor are all similar, if not identical, proteins now referred to as interleukin 1. As a result, it is apparent that investigators from many seemingly unrelated disciplines have a common interest in understanding better the biology of interleukin 1. The objective of the proposed conference is: 1. to gather researchers actively investigating various aspects of interleukin 1 to discuss the multiple physiologic, metabolic and immunologic actions of this exciting protein, 2. to describe the mechanisms involved in interleukin 1 production, release, and action, 3. to attempt to determine how the various activities attributable to interleukin 1 integrate the host's response to injury, infection, and inflammation, 4. to attempt to elucidate the role interleukin 1 plays in intercellular communication in health, 5. to attempt to identify the potential therapeutic value of: a. modulation of endogenous interleukin 1 concentration, or b. exogenous administration of interleukin 1, and 6. to assess how an understanding of interleukin 1 production and function can be used to develop drugs that modulate specific and nonspecific immunity.